Muffler



H. S. POWELL Oct. 1o, 193.9.

MUFFLER Filed April l, 1938 m Sw NJW @d NU NW www nuev/Qrv NU lw .Qwd .Q,NNWU 3.@ mmm msm Nw *Sw wmv mv SW #Sw www @SM am@ NHMQN @Sw sw ,www Aww QN m. WN m f i r J Nw mwN N l Rm f NJN QN ww. w .ww NN Wm gw www ww NNWN www ww .ww ww ww m ww ww E1 N ww @NW @QQ Q5 QN. d. NNW P d Patentedct. 10, 1939 UNITED STATES PATENT OFFICE 2 Claims.

The present invention relates to new and useful improvements in mulers,and more particularly to improvements in muiliers which are gen erallyused for quieting the noise incident to the exhaust from internalcombustion engines.

The present invention is concerned with the provision of a muffler ofthe type wherein one or more tubes extend partially or wholly throughthe mufller casing. In this type of muffler, the most usual forms arethe straight-through type or the tri-how type. In the first type, thereis generally provided a perforated tube, which extends substantiallythrough the muffler casing. Batlle plates are provided around the tubeso as to provide a plurality of expansion compartments for the gasespassing through the muiiler. Thus, the exhaust gases pass into theperforated tube and are successively expanded in the compartments duringthe passage thereof through the muflier to the outlet end. In the secondtype, a plurality of tubes are generally mounted within the mufliercasing in parallel relationship so that the exhaust gases pass in asinuous and reversely directed path through the muffler. In this type ofmuffler, there are also provided baille plates around the tubes andsecured to the muffier casing for affording compartments into which theexhaust gases are successively expanded as they pass through the varioustubes in the casing. The present invention is specifically conl cernedwith the provision of a muflier which combines the advantageous featuresof both of the above types of mufilers.

An object of the present invention is to provide a muflier which is ofrelatively simple construction, which is inexpensive to manufacture, andwhich effects the desired quieting of the exhaust gases.

A further object of the invention is to provide a muiiler of the abovetype, wherein a plurality of relatively short tubes are mounted withinthe muer casing, the adjacent ends of the tubes bing offset with respectto one another so as to cause the gases to pass through the mui-ller ina sinuous path.

A still further object of the invention is to provide a muflier of theabove type, wherein the adjacent offset ends of the tubes are spacedfrom one another to permit expansion of the exhaust gases therebetween.

A still further object of the invention is to provide a muflier of theabove type, wherein the tubes extend through baille plates which aresecured thereto and to the mufiler casing so as to afford expansionchambers for the gases during their passage therethrough.

The above and other objects of the invention will in part be obvious,and will be 4hereinafter more fully pointed out.

In the accompanying drawing,

Figure 1 is a side view, in section, showing one form of the improvedmuflier assembly.

Figure 2 is a similar side view, in section, showing a modified form ofthe improved muffler assembly.

Figure 3 is a sectional view taken along the line 3 3 of Figure 1.

Figure 4 is a sectional view taken along the line 4-4 of Figure 2.

Referring more in detail to the accompanying drawing, and particularlyto Figures 1 and 8, the muiller assembly is illustrated as including anouter muler casing I0 which is provided with end closures II, I2. videdwith outwardly extending flanges IIa, Ita, respectively, which aresuitably secured, as by welding, to the inner surface of the mufflercasing III. The end closures are centrally apertured and are providedwith inwardly extending fianges IIb, I2b, respectively, around thecentral apertures therethrough. An exhaust pipe I3 is provided with areduced end portion I3a which is disposed adjacent and within the flangeIIb of the end closure I I. disposed within the reduced end I3a of theexhaust pipe I3, and these parts are secure-d together and to the flangeIIb by welding or the like.

Baffie plates I5, I6 are provided with outer flanges I5a, IBa,respectively, which are secured to the interior surface of the mulercasing I0 by Welding or the like. rI'hese baffle plates I5, I6 are alsocentrally apertured and are provided with inner flanges I5b, IBb,respectively. The tube I4 extends through the apertures defined by theflanges I5b, IIib, and is secured thereto by welding or the like. Thetube I4 is thus centrally located with respect to the mufiler casing I0.A chamber I'I is thus provided between the end closure II and the bailieplate I5, and a similar chamber I8 is provided between the baffle platesI5 and I6. The tube I4 is perforated to provide communication with thechambers I'I, I8. As i1- lustrated in Figure 1, the tube is providedwith sets of elongated slots I9 which afford communication between thetube and the expansion chambers.

An outlet tube 2U is secured to the ange |21) on the end closure I2 atthe opposite end of the The end closures II, I2 are prot A tube I4 hasone end thereof muiller casing i0. This tube 2@ extends within themuffler casing, and baille plates 2l, 22 are provided with outer ilanges2id, 22a, respectively, which are welded or otherwise secured to theinner surface of the muiler casing lil. The baille plates 2l, 22 arealso centrally apertured and are provided with inner flanges 2lb, 22h,respectively. The tube 22 extends through the apertures dened by theinner flanges 2lb, 22D and is thus centrally located with respect to themufiier casing lil. The flanges 2lb, 22h are secured to the tube 2il bywelding or the like. A chamber 2li is thus provided around the tube 2Ubetween the baffle plates 2l, 22. A similar chamber 25 is providedaround the tube 23 between the baffle plate 22 and the end closure l2.Elongated slots 23 are provided in the tube 25) for aordingcommunication with the expansion chambers 24, 25.

The tubes ill and 20 are illustrated in Figure 1 as being in axialalignment, and the inner ends thereof are spaced apart a substantialdistance, as are the baffle plates l and 2l. Within the space betweenthe inner baille plates i6 and 2l, a central tube 26 is located.Intermediate baule plates 23, 2Q, 3B are disposed within the spacebetween the baffle plates i6, 2l, and are provided with outer ilanges28a, 23a, 32a, respectively, which are secured to the inner surface ofthe muiller casing lil. The intermediate baille plates are provided withaligned openings therethrough and with inner flanges 28h, 23h, 33hsurrounding these openings. The openings in the intermediate baffleplates are offset with respect to the openings in the baille plates atthe ends of the muiller casing, and the tube 26 extends through theseoffset Openings and is secured to the flanges 23h, 29h, 32h in anysuitable manner. The tube 22 is thus offset with respect to the endtubes i4, 263. The intermediate baffle plates 2B, 23, 3l) denneexpansion chambers 32, 33, and the tube 2S is provided with elongatedslots 2l which afford communication between the tube and these chambers.

The baille plates iii and 23 are spaced from one another, as are thebaille plates 2l and 3U, so that each end of the tube 23 is spaced fromthe adjacent end of the tubes lll and 2li. Thus, a chamber 3i isprovided between the baille plates i6 and 23, and a chamber 3d isprovided between the baffle plates 2l and 3?. Gases of combustionentering the tube ld from the exhaust pipe i3 are successively expandedin the chambers il, l 3 during their passage through the tube ifi. Theelongated slots i9 in the tube ifi permit a rapid expansion of the gasesinto the chambers il and i8. The gases issuing from the inner end of thetube lil are further expanded in the chamber 3l between the bailleplates i3 and 23. The gases then pass through the offset central tube 26and are further expanded in the chambers 32, 33 by passing through theslots 2l in the tube 26. The gases issuing from the opposite end of thetube 26 are further expanded in the chamber 34 between the baille plates2i, 30. From this chamber, the gases pass into the outlet tube 23 andare finally expanded in the chambers 23, 25 during the passage thereofthrough the elongated slots 23 in the tube 20.

In the modified form of muffler assembly shown in Figures 2 and 4, themuiller casing lil is provided with end closures 35, 36 which areprovided with outer flanges 35a, 36a, respectively, secured to the innersurface of the casing. The end closures 35, 33 are apertured at one edgethereof and provided with inner ilanges 35o, 36h, respectively, aroundthe apertures. At one end of the muier casing, spaced baffle plates 3l,38 are provided with outer flanges 31a, 38a which are secured, as bywelding, to the inner surface of the muffler casing. These baille platesare also apertured in alignment with the aperture through the endclosure 33, and a tube 39 extends through the apertures in the endclosure 35 and the baffle plates 3l, 38. The baffle plates 3l, 38 areprovided with inner ilanges 37b, 38D, respectively, which are securedaround the tube 39, as is the flange 35h on the end closure 35. The tube39 is provided with elongated slots 39a which communicate with chambersdi), lll dened by the end closure and the baille plates 3l, 38.

Spaced baille plates d2, i3 at the opposite end of the casing lil areprovided with outer flanges Md, 23d, respectively, which are secured tothe inner surface of the muffler casing l0. These baffle plates are alsoapertured in alignment with the aperture in the end closure 36, and areprovided with inner flanges l2b, 13b which are secured to a tube lfl, asis the flange 36h on the end closure 3G. The tube 411 is provided withelongated slots [lila which afford communication with chambers 55, dadeiined by the end closure 33 and the baille plates d2, 113. Thus, thetube il is illustrated as being in axial alignment with the tube 33 atthe opposite end of the muler casing, but it may be offset around theperiphery of the casing, if so desired.

The inner ends of the tubes 39, 44 are substantially spaced from oneanother, and the central portion of the mufiler casing between the endsof these tubes is provided with spaced baille plates di, 018, lill, theouter ilanges 47a, 48a, 49a, respectively, being secured, as by welding,to the inner surface of the muffler casing. The intermediate baffleplates lll, G8, 49 are provided with aligned apertures around whichinner flanges fl'lb, 33h, 29h, respectively, extend. These apertures areoset with respect to the apertures in the baffle plates at the ends ofthe casing, and a tube 553 extends through the apertures in theintermediate baille plates and is secured to the inner flanges l'ib,fllb, 43h. As shown in Figure 2, the central tube E@ is offset withrespect to the end tubes 39, lli a greater distance than the offsetshown in Figure i. Thus, there is no overlapping of the central tube 5Uwith the end tubes 39, lill, as in the construction in Figure l. Thecentral tube iii? is provided with elongated slots 56a which communicatewith chambers 5|, 52 dened by the intermediate baille plates.

The baille plates 3&3, /l are spaced from one another so as to providean expansion chamber 53 between the adjacent ends of the tubes 39 and5i). Similarly, the baffle plates 42, il-9 are spaced from one anotherto provide an expansion chamber 3G between the adjacent ends of thetubes 44 and 55. Exhaust gases entering the muffler through the tube 39are successively expanded in the chambers il by passing through theslots 33a. The gases issuing from the inner end of the tube 33 arefurther expanded in the chamber 53 and then pass into the central tube53. During the passage of the gases through the tube 53, they areexpanded into the chambers 5l, 52 and are further expanded in thechamber 5 at the outlet end of the tube 53. The gases then pass into thetube is at the opposite end of the mulller casing and are successivelyexpanded in the chambers 45, i6 before passing out of the muffler.

There is thus provided a muffler which combines the advantageousfeatures of a straightthroug type of mufller and the tri-dow type ofmufller. The gases are caused to pass through the muilier casing in asinuous path and are successively expanded into the expansion chambersdened by the spaced baille plates during their passage through themufller. This sinuous passage of the gases through the mulller casing isafforded by offsetting adjacent ends of the tubes Within the casing, andthe tubes are provided with elongated slots so as to assure rapidexpansion of the gases in the successive expansion chambers affordedWithin the muiller casing.

It is to be clearly understood that various changes in the detail ofconstruction and arrangement of parts may be made Without departing fromthe scope of the invention as set forth in the appended claims.

I claim:

1. A muiller comprising a casing, a plurality of spaced baille platessecured to the inner surface of said casing and affording a plurality ofexpansion chambers, a pair of perforated end tubes disposed within saidcasing and extending through a plurality of said baille plates at eachend of said casing for permitting the passage of gases into theexpansion chambers dened by said baille plates, said end tubes beingdisposed in axial alignment coincident With the axis of said casing andthe inner ends of said end tubes being substantially spaced from oneanother longitudinally of said casing, and a central perforated tubedisposed within the casing in the space between the inner ends of saidend tubes and having the axis thereof oiset with respect to the axes ofsaid end tubes, said central tube extending through baffle platesdisposed in the intermediate portion of said casing for permitting thepassage of gases into the expansion chambers defined by said baflleplates, the inner end of each of said end tubes and the adjacent end ofsaid central tube being spaced from one another and disposed in anexpansion chamber for permitting expansion of the gases when passingfrom one tube to another.

2. A muiller comprising a casing, a plurality of spaced baffle platessecured to the inner surface of said casing and affording a plurality ofexpansion chambers, and a plurality of tubes disposed within said casingand extending through a plurality of said baille plates, the adjacentends of said tubes being spaced from one another longitudinally of saidcasing, each of said tubes being provided with elongated longitudinalslots between adjacent baille plates for permitting the gases to passinto the expansion chambers defined by said baille plates, and at leastone of said tubes being offset with respect to and adjacent pair oftubes for providing a sinuous path for the gases through the muillercasing.

HERBERT S. POWELL.

